Title: Experiences with the Use of Shotcrete in Soft Rocks

Author(s): Alberto Marulanda and Luis F. Eslava

Publication: Symposium Paper

Volume: 54

Issue:

Appears on pages(s): 640-674

Keywords:

DOI: 10.14359/18052

Date: 1/1/1977

Abstract:
This paper refers to the application of shotcrete in tunnels driven through soft rocks which behave as squeezing ground. More than 15 km of tunnel have been successfully driven through those rocks using shotcrete as the main stabilization measure. The described experiences refer only to a small percentage of the total excavated lengthj, where local problems and cracks were evident in the shotcrete lining. The observational program which included instrumentation and observation of shotcrete behavior, indicated that shotcrete failure in soft rocks could be due to: a. Stress concentrations during the redistribution process around the tunnel that induce high tensile strains and cracking of the shotcrete. b. Inability of the shotcrete lining to resist the squeezing pressure when acting as acontinous lining (compression ring) with a compressive shear mode of failure.